This application claims the benefit of the Korean Patent Application No. P2001-08526 filed on Feb. 20, 2001, which is hereby incorporated by reference.
1. Field of the Invention
The present invention relates to a mobile communication system and, more particularly, to a method for measuring the traffic volume of transport channels in a mobile communication system.
2. Background of the Related Art
A medium access control (MAC) layer is included in a second protocol layer of a b 3rd generation partnership project (3GPP) architecture, which is one of the advanced network/wireless access systems, and it corresponds to a second layer of an open systems interconnection (OSI) 7-layer system. FIG. 1 illustrates the layers of a mobile communication system, including logical channels and transport channels. As shown in FIG. 1, the second layer (L2) of the 3GPP includes a packet data convergence protocol (PDCP) layer 210, a broadcast/multicast control (BMC) layer 220, and a radio link control (RLC) layer 230. In addition, the first and third layers of the 3GPP include a physical (PHY) layer 300 and a radio resource control (RRC) layer 100, respectively.
MAC layer 240 and RLC layer 230 are connected through logical channels (L_CH), and similarly, transport channels (T_CH) connect MAC layer 240 and PHY layer 300. MAC layer 240 maps the logical channels (L_CH) to the transport channels (T_CH) and selects the transport format combinations (TFC) of the transport channels, which are multiplexed based on the mapping source rate.
RLC layer 230 transmits the data stored in each RLC entity to MAC layer 240 through the logical channels, which are classified based on the type of each data set. MAC layer 240 transmits data received from RLC layer 230 to physical layer 300 through transport channels, which are classified based on the characteristics of the physical channels. Physical layer 300 converts the transport blocks received through the transport channels into frames and sends the frames through the physical channels. The transport format of data transmitted from MAC layer 240 to physical layer 300 is the information format of the transport blocks.
To enable RRC layer 100 to dynamically allocate radio resources based depending on the amount of data traffic, MAC layer 240 measures the data traffic volume of the transport channels and reports the measured traffic volume information to RRC layer 100. RRC layer 100 initially provides the lower and upper limits of the volume or the period information to MAC layer 240. These limits are used by MAC layer 240 when it measures the traffic volume of each transport channel in a periodic mode or an event triggered mode. If the system is set to the event triggered mode, MAC layer 240 reports the event to RRC 100 layer when the measured traffic volume is greater than the upper limit or less than the lower limit. For the periodic mode, MAC layer 240 periodically reports the measured traffic volume information to RRC 100 when a timer set to a given period expires.
As described above, regarding the background radio interface protocol structure, MAC layer 240 monitors the data traffic volume of RLC layer 230 to enable RRC layer 100 to properly allocate its radio resources. However, an actual embodiment of the structure is not standardized yet. In other words, the 3 GPP radio access network (RAN) standards simply state that the MAC layer measures the traffic volume and reports the measurement result to the RRC layer. The standards do not state the detailed processes of such measuring and reporting steps. For example, some processes/steps that need to be developed in detail are whether to perform the measurement and reporting on a radio bearer basis, on a logical channel basis, or on a transport channel basis; whether to include control protocol data units (Control PDUs) in the measured traffic volume; and what measurement will be used to compare with the upper/lower limits in the event triggered mode, etc. If such processes or steps are not described in detail, it will lead to great confusion in manufacturing the 3GPP systems and the related mobile stations.
The above references are incorporated by reference herein where appropriate for appropriate teachings of additional or alternative details, features and/or technical background.